It started with "family" movies, curiously enough, as toilet humor and double-entendre began threatening the G rating with extinction. Then horror movies always dependably R-rated tamed themselves into spooky-lite packages to make it easier for teens to get in. It was all part of the movie industry's plan to maximize audience and revenue, since R was too restrictive and G too wimpy. There, in the great middle, laid the biggest fortunes.

But equilibrium, an unchanging principle of nature and physics, mostly sucks in a theoretically artistic medium. Take the case of Accepted, a new film that wants to find its place in that underappreciated subgenre of American movie-making, the "slobs vs. snobs" comedy. Like its great-grandfather Animal House before it, Accepted is a tale of post-secondary also-rans.

After four years of underachievement, high school grad Bartleby Gaines (Justin Long) finds himself rejected by every college to which he applies. Unable to confess his failure to his parents, Bartleby creates a fictional college the South Hampton Institute of Technology with the help of a Web site constructed by his tech-savvy best friend Sherman (Jonah Hill). The abandoned psychiatric hospital they fix up becomes a home base for Bartleby's other left-out classmates, including an injured football star (Columbus Short) and a nerd (Maria Thayer) who fell short of her Ivy League ambitions. But South Hampton unexpectedly also attracts other bottom-percentile-dwellers, who believe they have been accepted with the click of a mouse.

It is, of course, a gag that can only head in one thematic direction. The snooty neighboring Ivory Tower institution with Anthony Heald, continuing his long career of slimy authority figures, as the dean will look down on its new makeshift neighbor, and there will be a battle in which unconventional methods will be proven educationally superior to rigidity.

Yet despite the schematic framework, Accepted often proves to be surprisingly funny. Long makes for an entertaining, fast-talking protagonist, and Hill has some terrific moments as the uptight foil. Lewis Black joins the festivities, essentially playing his fuming, finger-wagging self as the fake institution's cynical "dean." Even the college's name do the "acronym for South Hampton Institute of Technology" math becomes a goofy running gag.

That crude moniker, however, turns out to be something of a tease. As scripted by Adam Cooper, Bill Collage and Mark Perez, and directed by Steve Pink, Accepted begins as a rebel yell but refuses to go any farther than a PG-13 rating will withstand. Neither the slobs nor the snobs truly go for the gusto in fighting their adversaries. The sexy chicks like Bartleby's frat-boy-dating dream girl (Blake Lively) stay securely in nothing more risqu than bikini tops, and everyone remains curiously chaste. Even the final line of dialogue features a magic f-bomb that is actually bleeped out, because the writers had already used up their PG-13-authorized quota of one.

It's depressing, watching such number-crunched, corporate-mandated timidity in a movie that positions itself as anti-establishment. It would be nice to think especially in the wake of successfully envelope-pushing R-rated comedies like Wedding Crashers and The 40-Year-Old Virgin last summer that there's still a place for comedy without self-censorship based on the bottom line. Dean Wormer couldn't bring down the boys of Delta Tau Chi, but studio accountants just might.